1. Field of the Invention
The present invention relates to an image processing device, an imaging device, an image processing method, and a non-transitory computer readable recording medium recorded with an image processing program.
2. Description of the Related Art
Digital cameras which have a so-called manual focus mode that enables the user to manually adjust focus, in addition to an automatic focus using a phase difference detection method or a contrast detection method, have come into widespread use.
As a digital camera having a manual focus mode, a digital camera is known which is provided with a reflex mirror such that the user can adjust focus while checking an object and uses a split microprism screen on which a phase difference is visually displayed. In addition, a digital camera using a method which visually checks contrast is known.
However, in a digital camera without a reflex mirror which has recently come into widespread use, since a reflex mirror is not provided, there is no way to check an object image while displaying a phase difference and there is no choice but to use the contrast detection method. However, in this case, it is difficult to display an image with a contrast that is equal to or greater than the resolution of a display device such as a liquid crystal display (LCD). As a result, there is no choice but to use a method which partially enlarges an image and displays the image.
In recent years, a split image has been displayed in a live view image (also referred to as a through image) in order to make it easy for the user (for example, the photographer) to focus the camera on the object in the manual focus mode. The split image indicates, for example, a divided image (for example, each of the images which are divided in the up-down direction) in which the display region is divided into a plurality of regions and which deviates in a direction in which parallax occurs (for example, the left-right direction) depending on the amount of defocus. In a state in which an image is in focus, the deviation of the split image in the direction in which parallax occurs is removed. The user operates a manual focus ring (hereinafter, referred to as a “focus ring”) to focus the camera on the object such that the deviation of the split image (for example, each of the images which are divided in the up-down direction) is removed.
Here, the principle of the split image will be described. An object image which passes through a pair of regions of an imaging lens is pupil-divided and formed and a so-called right eye image and a so-called left eye are generated. Then, a split image is generated, using the right eye image and the left eye image. In addition, an object image which passes through the imaging lens is formed, without being pupil-divided, and a normal image is generated. Then, the normal image is displayed on a display unit and the split image is displayed in the normal image.
However, various techniques are known which enable the user to check whether an image is in focus. For example, an imaging device disclosed in JP2009-147665A displays a split image and gives the color information of a normal image to the split image in a case in which a phase difference satisfies a predetermined condition. Therefore, it is easy to visually recognize a display image indicating an in-focus state and a display image indicating an out-of-focus state.